High picture quality video streaming service method and system

ABSTRACT

The present invention relates to a high picture quality video streaming service method and system. The high picture quality video streaming service system according to the present invention includes: a content server for generating a first encoding video by encoding an original video with at a constant bit rate, generating a second encoding video by encoding the original video by using 1/N of the length of a first encoding video Group Of Pictures (GOP) and 1/N of a frame rate with constant Quantization Parameters, generating a streaming video by using the first encoding video and the second encoding video, and downloading the first encoding video and transmitting the streaming video in real time; and a user terminal for downloading and playing the first encoding video, or generating and playing a video for playback by recombining frames of the first encoding video and frames of the streaming video.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/113,445 filed Oct. 23, 2013, which is the National Phaseapplication of International Application No. PCT/KR2012/003316, filedApr. 27, 2012, which is based upon and claims the benefit of prioritiesfrom Korean Patent Application No. 10-2011-0061688, filed on Jun. 24,2011. The disclosures of the above-listed applications are herebyincorporated by reference herein in their entirety.

TECHNICAL FIELD

The present invention relates to a method and system for streaming highpicture quality video content and, more particularly, to a high picturequality video streaming service method and system, wherein a user candownload video content within a short time and streaming service can beprovided to a user based on already downloaded video content whenstreaming service for video content is provided to the user, therebybeing capable of providing high picture quality video content usingdownloaded video content even when streaming service is provided.

BACKGROUND ART

In general, in media streaming technology, multimedia data captured froma camcorder in real time is encoded by an encoder, and the encodedmultimedia data is transmitted to the media player of a terminal in theform of a multimedia stream which operates on the UDP/IP and RTP/RTCPlayers of a media server and is compressed by a codec over wired andwireless Internet networks in a streaming manner under the control of aReal Time Streaming Protocol (RTSP).

Here, the streaming service method is a method using a temporalcharacteristic of the multimedia data and is a method of playing backreceived data while continuously receiving a small amount of data over anetwork without downloading all data at once through the terminal. Thestreaming service method is a method suitable for providing long-timecontent as compared with a download method.

Furthermore, in a streaming service method, a Realtime Transfer Protocol(RTP) is now defined as a standard for streaming when a server sends acompressed video over a network so that a terminal can play back thevideo in real time. A transport method using an HTTP or an FTP is alsoused in the streaming service method. Video encoding technology in whichthe size of a video is reduced by compressing video data when streamingthe video is being used.

Meanwhile, a method of a user playing back a video in a terminalincludes a method of downloading video content and playing back thedownloaded video content, a method of receiving video content throughInternet streaming and playing back the received video content asdescribed above, and so on. Video download service is problematic inthat the time that is taken for a user to download video content islong, and streaming service is problematic in that it is difficult tosufficiently increase picture quality of a transmitted video due tolimited real-time transport.

DISCLOSURE Technical Problem

An object of the present invention for solving the aforementionedproblems is to provide a high picture quality video streaming servicemethod and system, wherein a user can download video content within ashort time and streaming service can be provided to a user based onalready downloaded video content when streaming service for videocontent is provided to the user, thereby being capable of providing highpicture quality video content to the user even when streaming service isprovided.

Technical Solution

In accordance with an aspect of the present invention for achieving theobject, a high picture quality video streaming service system includes acontent server for generating a first encoding video by encoding theoriginal video at a constant bit rate, generating a second encodingvideo by encoding the original video having a constant quantizationparameter in 1/N of a length of a Group Of Picture (GOP) and at 1/N of aframe rate of the first encoding video, generating a streaming videousing the first encoding video and the second encoding video,downloading the first encoding video, and transmitting the streamingvideo in real time and a user terminal for downloading the firstencoding video and playing back the downloaded first encoding video orgenerating a video for playback by recombining frames of the firstencoding video and frames of the streaming video and playing back thegenerated video for playback.

In accordance with another aspect of the present invention, a contentserver includes a first encoding unit for generating a first encodingvideo by encoding the original video at a constant bit rate, a secondencoding unit for setting a Group Of Picture (GOP) and a frame rate sothat a second encoding video is encoded in 1/N of the length of a GOPand at 1/N of the frame rate of the first encoding video and generatingthe second encoding video by encoding the original video with aquantization parameter constant for the entire original video, astreaming video generation unit for generating a streaming video usingthe first encoding video and the second encoding video, a video downloadunit for downloading the first encoding video, and a video streamingunit for transmitting the streaming video in real time.

Here, the streaming video generation unit compares frames of the firstencoding video with frames of the second encoding video and generates areserved streaming video by selecting a frame of the first encodingvideo if frames are identical with each other and selecting one of aframe of the first encoding video and a frame of the second encodingvideo if the frames are not identical with each other.

Furthermore, the streaming video generation unit predicts structuralsimilarity values when transmitting a frame of the first encoding videoand a frame of the second encoding video as the streaming video andgenerates the reserved streaming video by selecting the frame of thefirst encoding video if a difference between the predicted structuralsimilarity values is a threshold or lower and selecting the frame of thesecond encoding video if a difference between the predicted structuralsimilarity values exceeds the threshold.

Furthermore, the streaming video generation unit generates the streamingvideo by removing a frame identical with the frames of the firstencoding video from frames of the reserved streaming video.

In accordance with yet another aspect of the present invention, a userterminal includes a video download unit for downloading a first encodingvideo, a video streaming unit for receiving a streaming video in realtime, a playback video generation unit for generating a video forplayback using the first encoding video and the streaming video, and avideo playback unit for playing the first encoding video or playing backthe video for playback.

Furthermore, the playback video generation unit compares frames of thefirst encoding video with frames of the streaming video, selects a frameof the first encoding video if the frame of the first encoding video isincluded only in the first encoding video, selects a frame of thestreaming video if the frame of the streaming video is included in thefirst encoding video and the streaming video, and generates the videofor playback by recombining the selected frames.

In accordance with yet another aspect of the present invention, a highpicture quality video streaming service method of a content serverincludes the steps of (a) generating a first encoding video and a secondencoding video by encoding the original video at different Group OfPictures (GOP) and different frame rates, (b) generating a streamingvideo using the first encoding video and the second encoding video, and(c) downloading the first encoding video and transmitting the streamingvideo in real time.

Here, the step (a) includes generating the first encoding video byencoding the original video at a constant bit rate, a first Group OfPicture (GOP), and a first frame rate and generating the second encodingvideo by encoding the original video having a constant quantizationparameter in 1/N of the length of the first GOP and at 1/N of the firstframe rate.

Furthermore, the step (b) includes the steps of (b-1) comparing framesof the first encoding video with frames of the second encoding video andgenerating a reserved streaming video by selecting a frame of the firstencoding video if frames are identical with each other and selecting oneof a frame of the first encoding video and a frame of the secondencoding video if the frames are not identical with each other and (b-2)generating the streaming video by removing a frame identical with theframes of the first encoding video from frames of the reserved streamingvideo.

Furthermore, the step (b-1) includes predicting structural similarityvalues when transmitting a frame of the first encoding video and a frameof the second encoding video as the streaming video and generating thereserved streaming video by selecting the frame of the first encodingvideo if a difference between the predicted structural similarity valuesis a threshold or lower and selecting the frame of the second encodingvideo if a difference between the predicted structural similarity valuesexceeds the threshold.

In accordance with yet another aspect of the present invention, a highpicture quality video streaming service method of a user terminalincludes (a) downloading a first encoding video and receiving astreaming video in real time, (b) generating a video for playback usingthe first encoding video and the streaming video, and (c) playing backthe video for playback.

Here, the step (b) includes comparing frames of the first encoding videowith frames of the streaming video, selecting a frame of the firstencoding video if the frame of the first encoding video is included onlyin the first encoding video, selecting a frame of the streaming video ifthe frame of the streaming video is included both in the first encodingvideo and the streaming video, and generating the video for playback byrecombining the selected frames.

Advantageous Effects

As described above, the high picture quality video streaming servicemethod and system of the present invention are advantageous in that theycan provide high picture quality video streaming service at a low datatransfer rate using a downloaded video while providing download servicefor a video at high speed.

DESCRIPTION OF DRAWINGS

FIG. 1 is a construction diagram showing an embodiment of a high picturequality video streaming service system in accordance with an aspect ofthe present invention.

FIG. 2 is a construction diagram showing an embodiment of a contentserver in accordance with another aspect of the present invention.

FIG. 3 is a construction diagram showing an embodiment of a userterminal in accordance with yet another aspect of the present invention.

FIG. 4 is a flowchart illustrating a high picture quality videostreaming service method of the content server in accordance with yetanother aspect of the present invention.

FIG. 5 is a detailed flowchart illustrating a process of generating astreaming video in the high picture quality video streaming servicemethod of the content server in accordance with yet another aspect ofthe present invention.

FIG. 6 is a flowchart illustrating a high picture quality videostreaming service method of the user terminal in accordance with yetanother aspect of the present invention.

FIG. 7 is a detailed flowchart illustrating a process of generating avideo for playback in the high picture quality video streaming servicemethod of the user terminal in accordance with yet another aspect of thepresent invention.

FIG. 8 is a diagram illustrating an embodiment in which a streamingvideo is generated in the high picture quality video streaming servicemethod of the content serve in accordance with yet another aspect of thepresent invention.

FIG. 9 is a diagram illustrating an embodiment in which a video forstreaming playback is generated in the high picture quality videostreaming service method of the user terminal in accordance with yetanother aspect of the present invention.

MODE FOR INVENTION

The present invention may be modified in various ways and may beimplemented to have several embodiments. Specific embodiments areillustrated in the drawings and are described in detail. It is howeverto be noted that the present invention is not intended to be limited tothe specific embodiments of the present invention, but it is to beunderstood that the specific embodiments include all modifications,equivalents to substitutions which fall within the spirit and technicalscope of the present invention.

Embodiments of a high picture quality video streaming service method andsystem according to the present invention are described in detail withreference to the accompanying drawings. In describing the embodimentswith reference to the accompanying drawings, the same or correspondingelements are assigned the same reference numerals, and a redundantdescription thereof is omitted.

High Picture Quality Video Streaming Service System

FIG. 1 is a construction diagram showing an embodiment of a high picturequality video streaming service system in accordance with an aspect ofthe present invention.

The high picture quality video streaming service system 1000 inaccordance with an aspect of the present invention, as shown in FIG. 1,includes a content server 200, a user terminal 300, and a communicationnetwork 100.

The content server 200 generates a video for high-speed download(hereinafter used as the same meaning as a ‘first encoding video’) byencoding the original video at a constant bit rate, generates a videofor high picture quality (hereinafter used as the same meaning as a‘second encoding video’) by encoding the original video having aconstant quantization parameter in 1/N of the length of the Group OfPicture (GOP) of the first encoding video and at 1/N of the frame rateof the first encoding video, generates a streaming video using the firstencoding video and the second encoding video, downloads the firstencoding video, and transmits the streaming video in real time.

The first encoding video is a video encoded from the original video forhigh-speed download at a constant bit rate, and the second encodingvideo is a video encoded from the original video in the state in whichpicture quality of the original video remains constant for streaming.

The second encoding video encoded for streaming is encoded such that thelength of a GOP of the second encoding video is 1/N times and a framerate thereof is 1/N times, as compared with the first encoding videoencoded for high-speed download. Preferably, N may be set to 2.

The user terminal 300 downloads the first encoding video and plays backthe downloaded first encoding video or generates a video for playback byrecombining frames of the first encoding video and frames of thestreaming video and plays back the generated video.

That is, the user terminal 300 downloads a video for high-speeddownload, that is, the first encoding video, stores or plays back thedownloaded video or recombines a streaming video received in real timewith a video for high-speed download and plays back the recombined videoas a video for streaming playback.

The communication network 100 can include a mobile communicationnetwork, such as CDMA, WCDMA, or HSPA, a wired communication network,such as the Internet and a PSTN, and a local area communication network,such as Bluetooth or Zigbee.

Content Server

FIG. 2 is a construction diagram showing an embodiment of the contentserver in accordance with another aspect of the present invention.

The content server 200 is configured to include a first encoding unit210, a second encoding unit 220, a streaming video generation unit 230,a video download unit 240, and a video streaming unit 250, as shown inFIG. 2.

The first encoding unit 210 generates a first encoding video encodedfrom the original video at a constant bit rate.

The first encoding unit 210 generates a video for high-speed download byencoding the original video at a constant bit rate so that a videoencoded at a constant bit rate can be transmitted.

The second encoding unit 220 sets the length of a GOP and a frame rateof the original video such that the original video is encoded in 1/N ofthe length of the GOP of the first encoding video and at 1/N of theframe rate of the first encoding video and encodes the original video inthe state in which a quantization parameter is constant in the entireoriginal video.

The second encoding unit 220 encodes the original video so that picturequality of all videos remain constant using a quantization parametervalue for the entire original video as a constant value in order togenerate a video for high picture quality.

The streaming video generation unit 230 generates a streaming videousing the first encoding video encoded by the first encoding unit 210and the second encoding video encoded by the second encoding unit 220.

The streaming video generation unit 230 compares the frames of the firstencoding video with the frames of the second encoding video andgenerates a reserved streaming video by selecting the frames of thefirst encoding video, that is, a video for high-speed download if theframes are identical with each other and selecting one of the frames ofthe first encoding video and the frames of the second encoding video ifthe frames are not identical with each other.

The streaming video generation unit 230 predicts structural similarity(SSIM) values for frames that are not identical with each other whentransmitting frames of the first encoding video and frames of the secondencoding video as a streaming video and generates a reserved streamingvideo by selecting the frames of the first encoding video if adifference between the predicted SSIM values is a threshold or lower andselecting the frames of the second encoding video if a differencebetween the predicted SSIM values exceeds the threshold.

The streaming video generation unit 230 generates a streaming video byremoving the same frame as that of the first encoding video from theframes of the reserved streaming video.

For example, if the second encoding video has been encoded such that theGOP and frame rate of the second encoding video become ½ of the GOP andframe rate of the first encoding video, the streaming video generationunit 230 forms a reserved streaming video by selecting frames of thefirst encoding video in the case of the same ½ frames because ½ of allthe frames is the same as those of the first encoding video whencomparing each of the frames of the first encoding video with each ofthe frames of the second encoding video.

The streaming video generation unit 230 predicts a difference betweenSSIM values of ½ frames that are not identical with each other when thefirst encoding video and the second encoding video are transmitted as astreaming video, compares the predicted difference between the SSIMvalues with a threshold, and forms a reserved streaming video byselecting frames of the first encoding video if the difference betweenthe SSIM values is the threshold or lower and selecting frames of thesecond encoding video if the difference between the SSIM values exceedsthe threshold.

In accordance with the aforementioned process, the streaming videogeneration unit 230 forms a reserved streaming video and finallygenerates a streaming video by removing the same frame as that of thefirst encoding video from the frames of the reserved streaming video.

The video download unit 240 downloads the first encoding video (i.e., avideo for high-speed download), and the video streaming unit 250transmits the streaming video to the user terminal 300 in real time.

User Terminal

FIG. 3 is a construction diagram showing an embodiment of the userterminal in accordance with yet another aspect of the present invention.

The user terminal 300 is configured to include a video streaming unit310, a video download unit 320, a playback video generation unit 330,and a video playback unit 340, as shown in FIG. 3.

The video streaming unit 320 receives a streaming video in real time,and the video download unit 320 downloads a first encoding video.

The playback video generation unit 330 of the user terminal 300 cangenerate a video for playback by combining the downloaded first encodingvideo with the streamed streaming video and thus can play back a videofor high picture quality as a video for playback using the downloadedfirst encoding video in advance.

More particularly, the playback video generation unit 330 compares theframes of the first encoding video and the frames of the streamingvideo, selects the frames of the first encoding video if the frame isincluded only in the first encoding video, selects the frames of thestreaming video if the frame is included both in the first encodingvideo and the streaming video, and generates a video for playback byrecombining the selected frames.

The video playback unit 340 plays back the first encoding videodownloaded at high speed or plays back the video for playback generatedby recombining the downloaded first encoding video and the streamedstreaming video.

High-Picture Quality Video Streaming Service Method of Content Server

FIG. 4 is a flowchart illustrating a high picture quality videostreaming service method of the content server in accordance with yetanother aspect of the present invention, and FIG. 5 is a detailedflowchart illustrating a process of generating a streaming video in thehigh picture quality video streaming service method of the contentserver in accordance with yet another aspect of the present invention.

The high picture quality video streaming service method of the contentserver of the present invention includes, as shown in FIG. 4, generatinga first encoding video and a second encoding video (S410), generating astreaming video (S420), and downloading the first encoding video andtransmitting the streaming video in real time (S430).

Here, the step (S410) of generating the first encoding video and thesecond encoding video includes encoding the original video at differentGroup Of Pictures (GOPs) and different frame rates. The first encodingvideo, that is, a video for high-speed download, and the second encodingvideo, that is, a video for high picture quality streaming, aregenerated by encoding the original video using differently set encodingparameters.

More particularly, the first encoding video is generated by encoding theoriginal video at a constant bit rate, at a first GOP, and a first framerate, and the second encoding video is generated by encoding theoriginal video having a constant quantization parameter in 1/N of thelength of the first GOP and at 1/N of the first frame rate.

Next, the generation (S420) of the streaming video is performed byselecting, removing, or recombining some frames of the first encodingvideo and the second encoding video. A detailed process of generatingthe streaming video is described with reference to FIG. 5.

Finally, the first encoding video, that is, a video for high-speeddownload, is downloaded onto the user terminal, and the streaming videogenerated by recombining the first encoding video and the secondencoding video is transmitted to the user terminal in a real-timestreaming manner.

The process of generating a streaming video in the high picture qualitystreaming service method of the content server is embodied below. Asshown in FIG. 5, the process includes a process (S510) of generating afirst encoding video and a second encoding video and a process(S520˜S590) of generating a streaming video.

First, the process of generating a streaming video includes comparingthe frames of the first encoding video with the frames of the secondencoding video in order to determine whether or not the frames of thefirst encoding video and the second encoding video are identical witheach other (S520).

Here, the same frame means that the frames of the original video areidentical with each other and means that the frames of the firstencoding video and the second encoding video have been encoded underdifferent conditions.

If, as a result of the comparison, the frames are identical with eachother, frames of the first encoding video are selected (S530). If theframes are not identical with each other, SSIM values of the first andthe second encoding videos when they are transmitted as a streamingvideo are predicted and compared with a threshold (S540 to S570).

That is, a preliminary streaming video is generated by selecting framesof the first encoding video, that is, a video for high-speed download(S530), if the frames of the original video of frames of the firstencoding video are identical with the frames of the original video offrames of the second encoding video and selecting one of frames of thefirst encoding video, that is, a video for high-speed download, andframes of the second encoding video, that is, a video for high picturequality download, (S540 to S570) if the frames of the original videosare not identical with each other.

If the frames of the original videos are not identical with each other,SSIM values when transmitting the frames of the first encoding video andthe second encoding video as a streaming video are predicted (S540), anda difference between the predicted SSIM values is compared with athreshold (S550).

If, as a result of the comparison, a difference between the SSIM valuesis the threshold or lower, frames of the first encoding video areselected (S560). If a difference between the SSIM values exceeds thethreshold, frames of the second encoding video are selected (S570).

A preliminary streaming video is generated by gathering the selectedframes of the first encoding video or the selected frames of the secondencoding video (S580).

Finally, a streaming video to be streamed and transmitted in real timeis generated by removing the same frame as that of the first encodingvideo from the frames of the preliminary streaming video (S590).

High-Picture Quality Video Streaming Service Method of User Terminal

FIG. 6 is a flowchart illustrating a high picture quality videostreaming service method of the user terminal in accordance with yetanother aspect of the present invention, and FIG. 7 is a detailedflowchart illustrating a process of generating a video for playback inthe high picture quality video streaming service method of the userterminal in accordance with yet another aspect of the present invention.

The high picture quality video streaming service method of the userterminal includes, as shown in FIG. 6, downloading a first encodingvideo and receiving a streaming video in real time (S610), generating avideo for playback by recombining the first encoding video and thestreaming video (S620), and playing back a video for playback (S630).

The process of generating a video for playback in the high picturequality streaming service method of the user terminal is configured toinclude a process (S710) of downloading a first encoding video andreceiving a streaming video in real time, a process (S720˜S750) ofgenerating a video for playback by recombining the first encoding videoand the streaming video, and a process (S760) of playing back the videofor playback, as shown in FIG. 7.

Here, the process of generating the video for playback includescomparing the frames of the first encoding video with the frames of thestreaming video in order to determine whether or not the frames of thefirst encoding video and the streaming video are identical with eachother (S720). Whether or not the frames of the first encoding video andthe streaming video are identical with each other is determined bycomparing the frames of the original videos of the first encoding videoand the streaming video with each other.

If, as a result of the comparison, the same frame is included only inthe first encoding video, frames of the first encoding video areselected (S730). If the same frame is included both in the firstencoding video and the streaming video, frames of the streaming videoare selected (S740).

That is, a playback video is generated by commonly selecting the firstencoding video as a playback video, but additionally selecting frames ofthe streaming video in relation to frames transmitted as the streamingvideo.

Accordingly, high picture quality video streaming service can beprovided because frames of a higher picture quality video for high-speeddownload than a real-time streamed video can be used as a video forplayback.

Next, a video for playback is generated by combining the selected frames(S750), and the generated video for playback is played back (S760).

A process of the content server generating a streaming video and theuser terminal generating a video for streaming playback is described inmore detail with reference to FIGS. 8 and 9.

FIG. 8 is a diagram illustrating an embodiment in which a streamingvideo is generated in the high picture quality video streaming servicemethod of the content serve in accordance with yet another aspect of thepresent invention, and FIG. 9 is a diagram illustrating an embodiment inwhich a video for streaming playback is generated in the high picturequality video streaming service method of the user terminal inaccordance with yet another aspect of the present invention.

FIGS. 8 and 9 are diagrams illustrating a process of generating astreaming video using a video for high-speed download and a video forhigh picture quality when the video for high picture quality is encodedat ½ of the length of the GOP of the video for high-speed download andat ½ of the frame rate of the video for high-speed download and aprocess of generating a playback video using the video for high-speeddownload and the streaming video.

The generation of the streaming video includes, as shown in FIG. 8,includes generating, by the content server, a preliminary streamingvideo, by combining the video for high-speed download and the video forhigh picture quality and generating a streaming video by excluding thesame frame as that of the video for high-speed download from thepreliminary streaming video.

First, the frames of the video for high-speed download are compared withthe frames of the video for high picture quality. Frames of the videofor high-speed download, corresponding to the same frames in 2, 4, and 6rows, are selected as a preliminary streaming video.

Regarding frames in 1, 3, 5, and 7 rows which are not identical witheach other as a result of the comparison between the frames of the videofor high-speed download with the frames of the video for high picturequality, a difference between SSIM values when the video for high-speeddownload and the video for high picture quality are streamed andtransmitted is predicted and then compared with a threshold.

The 1 and 5 rows correspond to a case where the frames of the video forhigh-speed download have been selected as a preliminary streaming videoand where a difference between the SSIM values is the threshold orlower. The 3 and 7 rows correspond to a case where the frames of thevideo for high picture quality have been selected as a preliminarystreaming video and where a difference between the SSIM values exceedsthe threshold.

When the preliminary streaming video is generated by comparing each ofthe frames of the video for high-speed download with each of the framesof the video for high picture quality, a streaming video is generated byremoving frames of the video for high-speed download from thepreliminary streaming video.

The video for high-speed download is downloaded independently from thestreaming video. After the video for high-speed download is downloaded,the downloaded video is removed from the streaming video because thevideo for high-speed download can be used in the user terminal.

The playback video is generated by the user terminal using a video forhigh-speed download and a streaming video, as shown in FIG. 9.

First, the frames of the streaming video are compared with the frames ofthe video for high-speed download. Frames of the video for high-speeddownload, corresponding to frames in 1, 2, 4 to 6 included only in theframes of the video for high-speed download, are selected. A playbackvideo is generated by selecting frames of the streaming video,corresponding to frames included both in the video for high-speeddownload and the streaming video.

That is, in order to generate a playback video, the user terminalbasically uses the frames of a video for high-speed download which hasbeen previously downloaded and generates the playback video using onlyframes, transmitted as a streaming video, as the streaming videoadditionally.

As described above, in accordance with the present invention, a user candownload video content within a short time, and the user can be providedwith streaming service based on already downloaded video content whenbeing provided with streaming service for video content. Accordingly,high picture quality video content can be provided even when streamingservice is provided.

Although an exemplary client-server system is illustrated in thisspecification, the embodiment of a functional operation described inthis specification may be embodied in a different type of a digitalelectronic circuit from that described in this specification, or astructure disclosed in this specification and computer software,firmware, or hardware including structural equivalents thereof, or oneor more combinations of them. An embodiment of the subject that isdescribed in the present invention can be embodied as one or morecomputer program products, in other words, as one or more modulesregarding a computer program command that has been encoded on a programstorage medium in order to control the operation of a processing systemor to execute the computer program command on the processing system. Acomputer-readable medium may be a machine-readable storage device, amachine-readable storage substrate, a memory device, a composition ofmaterials that affect a machine-readable electromagnetic type signal, orone or more combinations of them.

The terms “processing system”, “processing device”, and “lower system”cover, for example, all pieces of equipment, devices, and machines forprocessing data, including a programmable processor, a computer, amultiple processor, or a computer. The processing system can include,for example, code that forms processor firmware, a protocol stack, andcode that forms an execution environment for a computer program when adatabase management system, an operating system, or one or morecombinations of them are requested, in addition to hardware.

A computer program (also known as a program, software, a softwareapplication, a script, or code) can be written in any type of aprogramming language that includes a compiled or interpreted language ortranscendental procedural language and can also be exploded in any typeincluding an independent program or module, a component, a subroutine,or other units suitable for being used in a computer environment. Thecomputer program does not need to necessarily correspond to a file of afile system. The program can be stored within a single file provided toa requested program, within multiple files that interface with eachother (e.g., a file that stores one or more modules, a lower program, orpart of code), or within part of another program or a file that includesdata (e.g., one or more scripts stored in a markup language document).The computer program can be placed in one site or distributed into aplurality of sites and can be exploded so that the computer program isexecuted on a single computer or multiple computers coupled togetherover a communication network.

A computer-readable medium suitable for storing a computer programcommand and data includes all types of non-volatile memories, mediums,and memory devices, including semiconductor memory devices, such asEPROM, EEPROM, and a flash memory device, magnetic disks, such as aninternal hard disk or an external disk, magneto optical disks, CD-ROMdisks, and DVD-ROM disk. The processor and the memory can besupplemented by a logic circuit of a special object or can be integratedinto a logic circuit of a special object.

An embodiment of the subject described in this specification can includea backend component, such as a data server, can include a middlewarecomponent, such as an application server, or can be embodied in anoperation system that includes one or more combinations of a frontendcomponent and a backend thereof, and middleware or frontend component,such as a client computer having a web browser or graphic user interfacecapable of interacting with the embodiment of the subject described by auser in this specification or a backend. The component of a system canbe accessed by any type of digital data communication, such as acommunication network, or a medium.

Although this specification includes the details of a plurality ofspecific embodiments, the details should not be construed as beinglimitative to any invention or a scope that can be claimed, and on thecontrary, the details should be construed as being a description ofcharacteristics that may be specific to a specific embodiment of aspecific invention. Specific characteristics described in thisspecification in the context of an individual embodiment may be combinedand implemented in a single embodiment. On the contrary, various typesof characteristics described in the context of a single embodiment canalso be implemented in a plurality of embodiments individually or in anyproper lower combination. Although characteristics may operate in aspecific combination and the characteristics may be initially depictedas claimed, one or more characteristics from a claimed combination canbe excluded from the combination in some cases, and the claimedcombination can be changed into a lower combination or a modification ofthe lower combination.

Likewise, although operations are depicted in specific order in thedrawings, it should not be understood that the operations must beperformed in specific order or sequential order shown to obtain apreferred result or all the illustrated operations must be performed. Ina specific case, multi-tasking and parallel processing may beadvantageous.

Furthermore, it should not be understood that the separation of varioussystem components of the aforementioned embodiments is necessary in allthe embodiments. It should be understood that the aforementioned programcomponents and systems may be integrated into a single software productor packaged into multiple software products.

As described above, those skilled in the art to which the presentinvention pertains will understand that the present invention may beimplemented in other detailed forms without changing the technicalspirit or essential characteristics of the present invention.Accordingly, the aforementioned embodiments should not be construed asbeing limitative, but should be construed as being only illustrativefrom all aspects. The scope of the present invention is disclosed in theappended claims rather than the detailed description, and it should beunderstood that all modifications or variations derived from themeanings and scope of the present invention and equivalents thereof areincluded in the scope of the appended claims.

INDUSTRIAL APPLICABILITY

The present invention can be applied to a system which serves videocontent to a terminal through download or streaming and can be appliedto content synchronization technology and real-time transmissiontechnology for consuming high picture quality content over a network.

Furthermore, the present invention can be applied to technology forreducing the size of video content by compressing the video content inorder to store and stream the video content.

Furthermore, the present invention can be applied to a device, system orthe like which transmits a video compressed in a server over a networkso that the video can be played back in real time.

The invention claimed is:
 1. A high picture quality video streamingservice system, comprising: a content server for generating a firstencoding video by encoding an original video at a constant bit rate,generating a second encoding video by encoding the original video havinga constant quantization parameter in 1/N of a length of a Group OfPicture (GOP) and at 1/N of a frame rate of the first encoding video,generating a streaming video using the first encoding video and thesecond encoding video, downloading the first encoding video, andtransmitting the streaming video in real time; and a user terminal fordownloading the first encoding video and playing back the downloadedfirst encoding video or generating a video for playback by recombiningframes of the first encoding video and frames of the streaming video andplaying back the generated video for playback, wherein the contentserver predicts structural similarity values when transmitting a frameof the first encoding video and a frame of the second encoding video asthe streaming video and generates the preliminary streaming video byselecting the frame of the first encoding video or the second encodingvideo based on both a difference between the predicted structuralsimilarity values and a threshold.
 2. A content server, comprising: afirst encoding unit for generating a first encoding video by encoding anoriginal video at a constant bit rate; a second encoding unit forsetting a Group Of Picture (GOP) and a frame rate so that a secondencoding video is encoded in 1/N of a length of a GOP and at 1/N of aframe rate of the first encoding video and generating the secondencoding video by encoding the original video with a quantizationparameter constant for the entire original video; a streaming videogeneration unit for generating a streaming video using the firstencoding video and the second encoding video; a video download unit fordownloading the first encoding video; and a video streaming unit fortransmitting the streaming video in real time; wherein the streamingvideo generation unit predicts structural similarity values whentransmitting a frame of the first encoding video and a frame of thesecond encoding video as the streaming video and generates thepreliminary streaming video by selecting the frame of the first encodingvideo or the second encoding video based on both a difference betweenthe predicted structural similarity values and a threshold.
 3. Thecontent server of claim 2, wherein the streaming video generation unitcompares frames of the first encoding video with frames of the secondencoding video and generates a preliminary streaming video by selectinga frame of the first encoding video if frames are identical with eachother and selecting one of a frame of the first encoding video and aframe of the second encoding video if the frames are not identical witheach other.
 4. The content server of claim 2, wherein the streamingvideo generation unit predicts structural similarity values whentransmitting a frame of the first encoding video and a frame of thesecond encoding video as the streaming video and generates thepreliminary streaming video by selecting the frame of the first encodingvideo if the difference between the predicted structural similarityvalues is the threshold or lower and selecting the frame of the secondencoding video if the difference between the predicted structuralsimilarity values exceeds the threshold.
 5. The content server of claim3, wherein the streaming video generation unit generates the streamingvideo by removing a frame identical with the frames of the firstencoding video from frames of the preliminary streaming video.
 6. A userterminal, comprising: a video download unit for downloading a firstencoding video; a video streaming unit for receiving a streaming videoin real time; a playback video generation unit for generating a videofor playback using the first encoding video and the streaming video; anda video playback unit for playing the first encoding video or playingback the video for playback wherein the user terminal communicates witha content server which predicts structural similarity values whentransmitting a frame of the first encoding video and a frame of thesecond encoding video as the streaming video and generates thepreliminary streaming video by selecting the frame of the first encodingvideo or the second encoding video based on both a difference betweenthe predicted structural similarity values and a threshold.
 7. The userterminal of claim 6, wherein the playback video generation unit comparesframes of the first encoding video with frames of the streaming video,selects a frame of the first encoding video if the frame of the firstencoding video is included only in the first encoding video, selects aframe of the streaming video if the frame of the streaming video isincluded in the first encoding video and the streaming video, andgenerates the video for playback by recombining the selected frames. 8.A high picture quality video streaming service method of a contentserver, comprising steps of: (a) generating a first encoding video and asecond encoding video by encoding an original video at different GroupOf Pictures (GOP) and different frame rates; (b) generating a streamingvideo using the first encoding video and the second encoding video; and(c) downloading the first encoding video and transmitting the streamingvideo in real time; wherein the content server predicts structuralsimilarity values when transmitting a frame of the first encoding videoand a frame of the second encoding video as the streaming video andgenerates the preliminary streaming video by selecting the frame of thefirst encoding video or the second encoding video based on both adifference between the predicted structural similarity values and athreshold.
 9. The high picture quality video streaming service method ofclaim 8, wherein the step (a) comprises generating the first encodingvideo by encoding the original video at a constant bit rate, a firstGroup Of Picture (GOP), and a first frame rate and generating the secondencoding video by encoding the original video having a constantquantization parameter in 1/N of a length of the first GOP and at 1/N ofthe first frame rate.
 10. The high picture quality video streamingservice method of claim 8, wherein the step (b) comprises steps of:(b-1) comparing frames of the first encoding video with frames of thesecond encoding video and generating a preliminary streaming video byselecting a frame of the first encoding video if frames are identicalwith each other and selecting one of a frame of the first encoding videoand a frame of the second encoding video if the frames are not identicalwith each other; and (b-2) generating the streaming video by removing aframe identical with the frames of the first encoding video from framesof the preliminary streaming video.
 11. The high picture quality videostreaming service method of claim 10, wherein the step (b-1) comprisespredicting structural similarity values when transmitting a frame of thefirst encoding video and a frame of the second encoding video as thestreaming video and generating the preliminary streaming video byselecting the frame of the first encoding video if the differencebetween the predicted structural similarity values is the threshold orlower and selecting the frame of the second encoding video if thedifference between the predicted structural similarity values exceedsthe threshold.